Posts Tagged soil organic matter

Today I actually found the time to read. Gardening for Profit is buried somewhere in the moving boxes, but I did manage to bring along my copy of The Biological Farmer. I’ll finish posting notes for Gardening for Profit when I get back to Oregon, but now seems like a good time to start sharing what I’m learning from Gary Zimmer.

This author runs a sustainable agriculture consulting firm in the upper Midwest and this book was originally intended to be a primer for consultants-in-training. He also owns and operates a 500-acre organic crop and dairy farm, and manages a 240-acre livestock and crop demonstration farm. It sounds like he’s heavily influenced by Albrecht, so I’m using this book as an introduction to soil-focused agriculture.

Some of the information isn’t new to me, since I studied environmental science and ecology in school. My eyes didn’t perk up till chapter 2, when he described 6 rules essential to biological farming. By “biological” farming, he means farming to maximize productivity and profits over time by understanding and working with biological processes (whereas conventional practices focus on maximum productivity and profits ASAP, and don’t give a @#$% about biological processes). He goes a step further and describes his criteria for sustainable agriculture, which can be achieved by practicing biological agriculture properly and in the long run: zero soil loss, nutrient balance, and 25 earthworms per cubic foot of soil.

OK, back to business. My plan had been to borrow a copy of The Biological Farmer by Gary Zimmer from the local university library. I’d been told it’s an excellent primer, and I’ve been looking for a source to provide me with a balanced context so I don’t get lost in the details. But before I could get my hands on a library copy, my schedule went to hell and now my “inside source” at the university has graduated. So then I was going to actually buy a copy, but tonight I came across another highly recommended book that’s available through the soil and health library nurtured by Steve Solomon (bless his heart). The book is Gardening for Profit by Peter Henderson and–get this–it was written and published in 1867! For a book to still be relevant and helpful over 200 years later [edit: 100 years later–math class, anyone?]…this I’ve got to read.

That library, by the way, it’s dangerous. There are so many goodies in there that I could easily blow a month’s paycheck in one sitting–I was so tempted to print out at least five books at once, but I practiced moderation and decided to print only one title, Gardening for Profit, at my local Fedex Kinko’s for $16. You can upload the PDF to their website and complete your order so that all you have to do is pick it up when it’s ready. I had my copy bound nicely so that it lasts a long, long time. I also paid the voluntary $15 to become a lifetime member of the soil and health library. Small price to pay for such a goldmine of knowledge!

Found an abstract which might explain how excess N messes with soil carbon sequestration:

“The added NO3- suppressed mineralization of C from SOM and stimulated mineralization of C from stover. Adjustment of rates of stover decomposition to temperature regimes normally encountered in Iowa fields after harvest showed that stover decomposition would not be complete within 1 yr and that increases in NO3- availability decreased the amount of stover C remaining in the soil. This effect of NO3- could explain how additions of unneeded N could decrease concentrations of SOM in long-term studies in which residues and NO3- are added in annual cycles. These observations suggest that practices that reduce unnecessary fertilization could help conserve SOM and reduce net amounts of CO2 released to the atmosphere.”

Next: My pathetic attempt to translate this into understandable terms after reading the whole study, if I can get my hands on it.

Update: No luck finding the full study after searching two state university library systems. Here’s the citation for this article in case anyone’s interested:

Title: NITROGEN EFFECTS ON CONSERVATION OF CARBON DURING CORN RESIDUE DECOMPOSITION IN SOIL

Now that I’ve read the compost study, Albrecht’s article on soil restoration, and the nitrogen myth article, I’m still left wondering how nitrogen directly impacts the formation of organic matter. Albrecht insists that there must be adequate nitrogen present in the soil or else carbon is lost (presumably as carbon dioxide). The compost study results back this up – more nitrogen resulted in more soil carbon. But then the nitrogen myth article implies that excess nitrogen (and I mean extreme, as in 60-190% net addition of N) also results in the loss of carbon from the soil. How does this work?

C + Excess N = CO2

C + Too little N = CO2

C + Just the right amount of N = Soil carbon

I think I need to get my hands on a soil science/microbiology textbook. Maybe I’ll peruse eBay and find a cheap copy that some college student spilled their beer on.

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This is a study journal to accompany SelfmadeFarmer.com. The main purpose of it is to organize my thoughts and research about farming in one place; a secondary purpose is to share it with anyone who wants to follow along and learn with me.

If we let ourselves, we shall always be waiting for some distraction or other to end before we can really get down to our work. The only people who achieve much are those who want knowledge so badly that they seek it while the conditions are still unfavourable. Favourable conditions never come... We must do the best we can.- C.S. Lewis